The present disclosure relates to a coating machine component, for example, a bell cup for a rotary atomizer and an appropriate production method.
In modern painting plants for coating vehicle body parts, rotary atomizers are primarily used as the paint applications devices which have a rapidly rotating bell cup which sprays and atomizes the paint to be applied due to the centrifugal forces acting on the paint.
One objective for designing such bell cups is to achieve the lowest possible weight in order to reduce the mechanical loading the bell cup exercises on the bearing unit or the compressed air turbine acting as the drive unit due to the very high rotational speed. Furthermore, a lowest possible weight of the bell cup offers advantages to minimize the forces involved in braking and accelerating the bell cup and therefore to reduce the danger of ejection of the bell cup which would represent a very high risk of an accident occurring.
On the other hand the design of the bell cup must achieve an adequate rotational speed strength so the materials used must demonstrate an adequate strength. Therefore conventional bell cups are usually made out of titanium or aluminum in order to achieve an adequate strength for the lowest possible weight.
A so-called combined bell cup is also known, for example, from EP 1 317 962 B1 and DE 20 2007 015 115 U1. Such combined bell cups consist of a material combination made out of a light material with a relatively low strength and a heavy material with a high strength in order to obtain a bell cup with the lowest possible weight and the highest possible strength. Therefore the combined bell cups consist of a number of components made out of various materials, the various components being connected to each other during assembly. However, also such types of combined bell cups still do not achieve a satisfactory compromise between the design goals of achieving the lowest possible weight on the one hand but also the highest possible strength on the other.
Further coatings are known, for example, from DE 44 39 924 A1, US 4 398 493 A, WO 90/01568 A1 and US 5 249 554 A.
For the sake of completeness one should also refer to conventional bell cups which have a friction reducing coating or a wear reducing coating, the coating not, however, having any influence on the weight and mechanical strength of the bell cup. Such bell cups with a wear reducing or a friction reducing coating are known, for example, from DE 101 12 854 A1 and DE 10 2006 022 057 B3.
It is therefore an object of the present disclosure to provide a bell cup which has the lowest possible weight and the highest possible strength. A further object of the invention is to provide a suitable manufacturing process.